This application outlines our proposal to develop a new Breast Cancer Research Program within Mayo's Comprehensive Cancer Center. The objectives of this initiative are to stimulate and coordinate new breast cancer research within Mayo, as well as between Mayo and other institutions. With its large clinical practice, Mayo has traditionally emphasized clinical research via prospective clinical trials. However, a substantial basic science program has been developed at Mayo which possesses a broad range of expertise directly applicable to the study of breast cancer. Numerous basic scientists have been identified with a commitment to breast cancer research. The primary goal of this application is to support the development of a new Breast Cancer Research Program which recruits basic scientists and clinicians to work together in a focused, multidisciplinary interactive research effort. The programmatic objectives are: 1) To advance our understanding of the biology of breast cancer, with particular emphasis on mechanisms of carcinogenesis and tumor progression. 2) To determine the clinical relevance of these fundamental observations in human breast cancer, with particular emphasis on early events in breast carcinogenesis. 3) To use our understanding of these early events to develop innovative strategies for cancer control and prevention. The new research initiatives proposed in this application include: 1) the establishment of an intramural peer-reviewed pilot project award mechanism to stimulate new activity in breast cancer research, 2) the initiation of a bimonthly seminar series devoted to the topic of breast cancer, and 3) the initiation of an annual breast cancer research retreat. We believe May is uniquely positioned to advance our understanding of the biology of breast cancer and to rapidly translate these discoveries into clinical practice. Through these efforts, our ultimate goal is to decrease the individual and societal burden of breast cancer.